1. Field of the Invention
The present invention relates to conveyor belting and to methods of manufacture of conveyor belting. More particularly, the belting of the present invention is a double-scrim belting comprising two spaced apart and generally parallel scrims having an intermediate fibrous material disposed therebetween.
One embodiment of the belting of the present invention comprises a first woven scrim and a spaced apart and substantially parallel second woven scrim connected by staple fibers consolidated together through entanglement and integrated with the scrims through entanglement, both entanglements being of the kind typically produced by needling. If desired, a non-woven web of staple fibers is needled to the outer surfaces of the scrims and the thusly formed belting can be encapsulated in a matrix of elastomeric material. If the belting is intended to be used to convey food grade products, an antimicrobial agent can be incorporated into the elastomeric material to inhibit bacterial growth. The textile yarns comprising the scrims and the fibrous layers can also have incorporated therein an antimicrobial agent.
In another embodiment of the double-scrim belting of the present invention, a fibrous layer is bonded between a pair of spaced apart and parallel scrims to form a laminated belting. Fibrous layers can be bonded to either or both of the outer major surfaces of the scrims and the resulting laminated belting can be encapsulated in an elastomeric material that can have an antimicrobial agent incorporated therein. The textile yarns comprising the scrims and the fibrous layers can also have an antimicrobial agent incorporated therein.
2. Prior Art
U.S. Pat. No. 4,154,335 to Burnett et al., which is assigned to the assignee of the present invention and incorporated herein by reference, describes a belting comprising a layer of staple fibers consolidated together through entanglement and integrated with a single layer open weave scrim through entanglement. Both entanglements are of the type produced by a needling operation. This belting can be calendared and heat set, followed by saturation with a polymeric elastomer material.
U.S. Pat. No. 4,157,752 to Sick et al. describes a belting comprising a layer of staple fibers consolidated together through entanglement and integrated with a single layer open weave scrim through entanglement. Both entanglements are of the type produced by a needling operation. This belting is encapsulated in a matrix of flexible elastomer or resin. Included in the integral structure is an impression wear surface of raised matrix material containing a portion of the consolidated staple fibers. This single scrim construction formed as an endless belting is not as sturdy under continuous duty conditions as the belting of the present invention.
U.S. Pat. No. 4,813,533 to Long describes a conveyor belting having a plurality of individual woven fabric layers having an intermediate non-woven mat or batt of entangled or spun-bonded staple fibers disposed therebetween. The non-woven fabric layer aids in absorption of a liquid polymeric resin saturant which encapsulates the fabric layers. However, the non-woven fabric layer is not needled to the woven fabric layers but instead is held together by reinforcing cords which join the fabric layers.
U.S. Pat. No. 3,190,137 Adams, Jr. describes a belting manufactured by depositing and adhering fiber-flock onto the unvulcanized rubber surface or rubber surface portions of the belting. The thusly constructed belting is then vulcanized whereby rubber flows around, immerses and bonds the fibers of the fiber-flock to provide a belting having a bonded fiber traction surface. In the belting of the present invention, the staple fibers are consolidated together and disposed intermediate the double scrims. This benefits belt wear under continuous duty conditions.
U.S. Pat. Nos. 4,787,516 to Morrison, 5,069,907 to Mixora et al. and 5,238,749 to Cueman et al. describe the use of the antimicrobial agent 5-chloro-2-(2,4-dichlorophenoxy) phenol to inhibit bacterial growth in various devise. However, the use of this antimicrobial agent in a belting is not disclosed.